peters



(No Model.) A

' .H. MGDONALD.

Furnace-Shield.

Patented June8, 1880.

NJETERS, FrioraumocmPHER. WASHINGTON. Dv I:A

UNITED STATES PATENT OEEICE.

HUGH MGDONALD, OF ALLEGHENY, PENNSYLVANIA.

FuRNAcE-sl-lIELD.v

SPECIFICATION forming part of Letters Patent No. 228,548, dated June 8, 1880.

Application filed April 2, 1880.

To all whom it may concern:

Be it known that I, HUGH McDoNALD, of Allegheny, county of Allegheny, State of Pennsylvania, have invented or discovered a new and useful Improvement in Furnace- Shields; and I do hereby declare the following to be a full, clear, concise, and exact description thereof, reference being' had to the accompanying drawings, making a part of this specification, in which-like letters indicating like parts- Figure l is a side elevation,A slightly in perspective, of a puddling or boiling furnace, showing my improved furnace-shield applied thereto; and Fig. 2 is a sectional view of the shield in the line .rx and through the door and adjacent wall of the furnace, and illustrativc of the relation of the two when in use.

Various forms of constructions of furnaceshields have been devised by which to protect the workman from the excessive heat generated in metallurgicl operations. The present improvement in furnace-shields is designed for that end, and it differs from other shields heretofore known chiefly in the fact that I combine with the ordinary iron shield plate or frame a second metallic plate having a comparatively low conducting or radiating power, whereby the injurious or objectionable radiation of heat is eftectually prevented and vthe workman properly protected.

A may represent a puddling or boiling or other furnace for metallurgie purposes, in which an excessive heat is required.

Opposite the door D, and at a litt-le distance therefrom, as shown in Fig. 2, so as to leave room for the circulation of air, I arrange my improved shield B, which is made up of the usual back or frame plate b, usually of wrought-iron, and secured thereto in any convenient way, as by rivets and distance-pieces c, an exterior plate, b', having the same general contour, but made ofzinc or other metal having a comparatively low power as an absorbent, conductor, or radiator of heat.

The exterior plate, b', may be placed directly against the plate b,- but I prefer to separate them a short distance, so that air may circulate freely between the two, and thereby lessen materially what little tendency the exterior plate may have for absorbing heat radiated from the other plate.

The shield thus constructed is made, by preference, large enough to coverabout so (No model.)

much of the furnace-wall as comes opposite to the position usually occupied by the workman in doing his work, and for paddling-furnace use is recessed, as at d, so as to uncover the stopper-hole of the furnace.

Any suitable means of holding the shield in the proper position for use and removing it out of the way when its presence is not desired may be employed; but preferably I hang it, by straps e and friction-rollers e', on a raised track-rail, a, which is supported by brackets a', and in such manner that the shield may be moved laterally out of the way, when desired, to about the position shown by dotted lines, and for this purpose handles b2 are provided.

If further protection is desired, an additional sheet of zinc or other suitable material, as above stated, may be arranged on the back side of the plate b, and be either bolted close to the plate, as at s, or adjusted at a little distance therefrom, as with b; or, the plate b being omitted, such plate s on the back side of plate b may be used as 'a substitute therefor in the combination described but for most purposes it is believed that one non-conducting plate is enough, and that the best place for it is on the front side of the plate b and at a little distance therefrom.

The plate b, of wrought or4 cast iron or steel, gives to the shield the necessary elements of strength and durability as against the rough usage commonly met with from iron-workers, and the non-conducting or low.- conducting plate b is held and carried thereby, so as to act as a protection to the workman when necessarily exposed in doing his work.

Other useful elements of furnace-shield construction, as the same may be known in the art, may be added to the construction described, as the manufacturer or user may desire.

I claim herein as my invention- In the construction of furnace-shields, the combination, with the body of the shield, of one or more plates of zinc or other low or poor-conducting metal, substantially as set forth.

In testimony whereof I have hereunto set my hand.

HUGH' McDONALD. Witnesses:

R. H. WHiTTLEsEY, O. L. PARKER.

IOO 

